The invention relates to a motor vehicle front face of the metal/plastic composite type.
A front face module is a structural element capable of incorporating various items of vehicle equipment such as headlamps, turn indicators, horn, heat exchanger, motor-fan unit or complete cooling module, etc. This module, thus fitted with its equipment, constitutes a prepared individual element delivered by the equipment manufacture and ready for the motor vehicle manufacturer to fit onto the vehicle.
This individual module is fitted by connecting it to lateral structural elements of the vehicle such as side rails, wings or shells, then by fitting a bumper or front valance attached to the module. A front face such as this is generally produced in the form of a one-piece element, particularly in the form of a metal/plastic composite element.
It is known practice, particularly from publication EP-A-0 658 470, to produce a front face in the form of a metal skeleton made of pressed sheet metal over which a plastic, particularly of the polyamide type, is overmolded. It is also known practice for a bumper beam, which contributes towards protecting the components of the module in the event of a front impact, to be associated with the front face.
It is also known practice for a front face to be produced in the form of a metal tube created by hydroforming, over which a plastic is overmolded, this in particular being performed using hydroplast technology (hydroplast being a trade name of General Electric).
The design of a front face is generally based on an analysis of the loadings that the various parts that make up the front face are liable to experience.
The pressed sheet metal skeleton technology offers the greatest simplicity but is of limited rigidity. Hydroformed tube technology offers better performance, but at a greater weight and higher cost.